Devices for delivering special fluids (e.g., antibiotics, blood, anesthesia and the like) to a patient by way of conventional administration sets are known. For example, it has long been known to load a simple syringe with a fluid and inject the fluid into the tubing of an administration set delivering primary fluid to a patient. Once in the tubing, the special fluid (hereinafter referred to as secondary fluid) is directed to the patient with the flow of the primary fluid in the set. This approach has the benefit of not requiring a second infusion pump and a second catheter site.
Unfortunately, many secondary fluids are not compatible with the primary fluid of the set and, when mixed, they may form dangerous precipitates. Another undesirable, but less dangerous, characteristic of some combinations of primary and secondary fluids is a tendency for the two fluids to not mix well, resulting in the administration of the secondary fluid at a rate other than the desired rate.
To remedy the problems caused by fluid incompatabilities, devices have been developed which isolate the secondary fluid for transmission to the patient as a bolus, thereby insuring a proper flow rate without necessitating a second pump and catheter site. Unfortunately, these devices are relatively complex and typically not reusable; therefore, they may represent a significant expense to a cost conscious hospital administration.